An electricity storage cell in which an electricity storage laminated body formed by laminating a cathode, an anode and a separator is accommodated in an electricity storage case constituted by a block-shaped outer shell and a laminate film has been known (PTL 1). It is possible to perform an operation at a desired voltage by connecting the electricity storage cells in series in the manner of stacking the electricity storage cases. Since the shape of the electricity storage cell is defined by the blocked-shaped outer shell, it is possible to easily stack the electricity storage cases.
An electric double layer capacitor (an electricity storage cell) in which an electricity storage laminated body is interposed between laminate films and the laminate films are fusion-bonded has been known (PTL 2). In the case of the method in which the laminated films are fusion-bonded, and thus a block-shaped outer shell is unnecessary, it is possible to efficiently and simply assemble the electricity storage cell.